Red mud catalyst

The preceding test was repeated with 20 g of Jamaican red mud catalyst replacing the red bauxite at 420 °C. The results in Figure 3 indicate that up to 20% water vapor slightly inhibited the sulfur dioxide conversion on this iron-rich catalyst. In absence of water, carbonyl sulfide was formed (curve a), but with water, hydrogen sulfide (curve c) was formed instead. 

Single-Bed, Nonisothermal Catalysts. In an attempt to circumvent the undesirable formation of hydrogen sulfide in the presence of water vapor, a nonisothermal reactor was constructed by placing 536 g of Jamaican red mud catalyst in a 2-cm diameter 96%-silica tube. The catalyst-filled tube was inserted into the bottom half of the furnace. This resulted in a 15-cm uniform temperature hot zone and a 25-cm zone with temperatures gradually decreasing to about 100 °C at the lower reactor exit. The inlet gas consisted of 17% water vapor, 5.8% carbon monoxide, and 3.0% sulfur dioxide, and 74.2% helium. Figure 5 shows the dependence of the exhaust gas analysis on the hot-zone temperature of the Jamaican red mud catalyst. No sulfur dioxide was removed at hot-zone temperatures lower than 240 °C. At 250 °C, some sulfur dioxide was removed, and small quantities of hydrogen sulfide were formed. Above 300°C, more than 80% of the sulfur dioxide and virtually all of the carbon monoxide... 

Figure 5. Effect of temperature of Jamaican red mud catalyst on exhaust gas analysis. Inlet gas 3% sulfur dioxide, 5.8% carbon monoxide, and 17% water vapor in helium.

Figure 7. Effect of second catalyst temperature on the exit gas composition. a,b = Surinan red mud catalyst. Inlet gas to first catalyst 0.57% sulfur dioxide, 0.89% carbon monoxide, and 7% water vapor in helium. a, b — Berbece bauxite in second catalyst. Inlet gas to first catalyst 0.44% sulfur dioxide, 0.80% carbon monoxide, and 20% water vapor in...

Other process concepts similar to those outlined previously have also appeared in the literature from time to time and an example of such a process is the disposable catalyst process (Figure 19.21) in which the coal (dried and slurried with a recycle oil) is mixed with an iron-containing (red mud) catalyst after which hydrogen (2000-4000 psi) is added and the whole is introduced into the reactor. The reactions occur in the liquid phase and the liquid product is separated by distillation to produce a liquid fuel oil and a heavier slurrying oil as well as residuum-type oil. This latter product may be processed further to yield further quantities of lighter products. 

Waste-plastic-derived oil that was prepared by thermal degradation of municipal waste plastics at 410°C was dehydrochlorinated to remove chloroorganic compounds using various catalysts such as iron oxide, iron oxide-carbon composite, ZnO, MgO and red mud. The iron oxide catalysts were effective in removing the chloroorganic compounds. MgO and ZnO catalysts were deactivated during the reaction by HCl, which is produced by the dehydrochlorination of chloroorganic compounds. Iron oxide and its carbon composite were found to be stable in the dehydrochlorination of municipal waste plastic derived oil [19]. 

The samples were dried, pulverized to 100 mesh, briquetted into minus 16- plus 20-mesh pellets, and indurated at 600 °C for 6 hr. The chemical and physical properties of these catalysts are given in Table I. The Berbece bauxite, a product of British Guiana, was obtained from Milwhite Co., Inc., Houston, Tex. The Arkansas red bauxite was obtained from David New-Minerals, Providence, Utah. The Jamaican and Surinam red mud samples were supplied by the Federal Bureau of Mines Albany Metallurgy Research Center, Albany, Oreg. 

When an iron-rich catalyst such as Jamaican red mud (20 g at 380°C) was used in this test, it not only exhibited much higher levels of catalytic activity, but it was also only slightly affected by the presence of up to 25% water vapor in the inlet gas. This is demonstrated by curve c of Figure 1. Thus, in order to suppress the adverse effect of water vapor on the catalytic reduction of sulfur dioxide with carbon monoxide,... 

Double-Bed Catalysts. Because the temperature of the colder section in the nonisothermal catalyst bed could not be readily controlled, an apparatus was constructed that contained two separate furnaces, each containing 20 g of Surinam red mud. The temperature of the first bed was varied to determine the optimum operating conditions with an inlet gas of 0.57% sulfur dioxide, 0.89% carbon monoxide, and 3% water vapor in helium. The exhaust gas analyses from the first furnace are shown in Figure 6. These results indicate that the hydrogen sulfide and sulfur dioxide removal efficiency increases with temperature up to about 400 °C. Beyond this temperature there is little improvement. 

Curve a represents the data with Surinam red mud in the second catalyst... 

Additional tests with 20 g of Surinam red mud in the double-bed catalyst were conducted with sulfur dioxide-rich gases, simulating a smelter gas. The temperature of the first reactor was 475 °C and that of the second was 230 °C. The inlet gas into the first catalyst bed contained 3.15% sulfur dioxide, 5.97% carbon monoxide, and 3% water vapor in helium. After several hours, the exhaust gas analyses from the sec-... 

Mohammed (84) used a Mn/Fe catalyst (B) which was precipitated batchwise and activated in a fluidized bed. For reasons of comparison Mohammed also did some measurements with untreated red mud activated at 270 in a fixed bed. The Kq value evaluated from Moheuxuned s results reveal a wide scatter cind are not shown in Fig. 20. The red mud is very active compared to the Mn/Fe catalyst but its selectivity to C2 to C4 olefins is poor. Compared to the Mn/Fe catalyst (B) of Mohemmed the catalyst (B) is more active by a factor of 6 to 10. This result presents a considereible improvement and underlines the importance of catalyst preparation (14). In addition, the high activity catalyst precipitated continuously and reduced in the slurry phase is as selective with regard to C2 to C4 olefins as the low activity catalyst of Mohammed (84). The Fe/Cu catalyst (C) precipitated continuously is again considerably more active than the Mn/Fe catalyst (D). However, the last one reaches the same activity only at a temperature of 300 °C which the Fe/Cu catalyst already has at 220 °C. 

The reaction conditions used in the first phase (sump phase) are generally temperatures of 400 to 500 °C and pressures ranging from 100 to 700 bar. Molybdenum and tungsten oxides are commonly used as catalysts, together with iron compounds. In the /G-hydrogenation process, Bayer-mass ( red mud ), a by-product of bauxite processing, was used as an iron catalyst. Coals which contain mineral compounds with the necessary catalytic activity can be hydrogenated without the addition of catalysts. 

Mannheim between 1921 and 1927. The first commercial plant was built at Leuna in 1927. Twelve plants of this type provided much of the aviation fuel used by Germany in World War II. After the war, the process was further developed by the U.S. Bureau of Mines. The process is essentially one of hydrogenation at high pressures and temperatures, catalyzed by an iron oxide catalyst. In Germany, the catalyst was the red mud waste from the Bayer aluminum process. See also Bergius-Pier. 

L6pez, A., et al., 2011. Catalytic pyrolysis of plastic wastes with two different types of catalysts ZSM-5 zeolite and Red Mud. Applied Catalysis B Environmental 104 (3—4), 211—219. 

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